Method and apparatus for suppressing fumes with charged aerosols



A. M. MARKS March 31, 1970 METHOD AND APPARATUS FOR SUPPRESSING FUMES WITH CHARGED AEROSOLS Filed Oct. 5. 1966 FIG. 4

zox/p United States Patent 3,503,704 METHOD AND APPARATUS FOR SUPPRESSING FUMES WITH CHARGED AEROSOLS Alvin M. Marks, 153--16 th Ave., Whitestone, N.Y. 1135.7 Filed Oct. 3, 1966, Ser. No. 583,749 Int. Cl. B03c 3/01, 3/38 US. Cl. 232 9 Claims ABSTRACT OF THE DISCLOSURE Noxious fumes are neutralized and detoxified as they pass through a conduit by mixing them with a liquid droplet aerosol simultaneously charged and formed by an array of fluid dispensing capillary tubes and a charging electrode spaced down stream of the tubes. The fumes are entrained, absorbed and/or reacted by the minute droplets which may also contain reactants to react with the gas. A discharge electrode neutralizes the charge on the aerosol droplets following which, they coalesce to form larger collecta'ble bodies.

This invention relates to fume suppressors and more particularly to the control, neutralization, detoxification, and disposal of pollutants resulting from combustion such as internal combustion engine exhaust, gas borne industrial and residential waste and the like.

The control of pollutants resulting from combustion has been particularly difficult because of the minute nature of many of the fume particles and the complexity of the products of combustion. Where the particles are of some size such as fly-ash or dust, filters and electric precipitation have been employed with some effect. However, the smaller particles pass through such devices into the air causing substantial contamination.

In the case of internal combustion engines there have been provided devices for passing the exhaust gases back through the engine in an effort to reduce atmospheric contamination.

Accordingly, it is an object of the present invention to provide a device for removing pollutants from the gases of combustion.

Another object of the present invention is to provide a device which will render the exhaust from internal combustion engines relatively harmless when discharged into the atmosphere.

A further object of the present invention is to provide a fume suppressor which is extremely simple in construction and operation.

Still another object of the present invention is to provide an inexpensive fume suppressor which will occupy a minimum of space.

Another object of the present invention is to provide a fume suppressor which is adapted for use on selfpropelled vehicles.

A feature of the present invention is its use of a charged aerosol in purifying exhaustgases by entraining minute particles.

Another feature of the present invention involves the use of a reactant for a component of the fumes in the carrier gas, said reactant being dissolved in the aerosol droplet.

Still another feature of the present invention is its use "ice of a high DC. voltage source to charge the aerosol particles as they pass through the device.

A further feature of the present invention is the neutralization of the charged aerosol particles and the entrained pollutants to form a disposable liquid.

The invention consists of the construction, combination and arrangement of parts, as herein illustrated, described and claimed.

In the accompanying drawings, forming a part hereof, there are illustrated three forms of embodiment of the invention, in which drawings similar reference characters designate corresponding parts, and in which;

FIGURE 1 is a somewhat diagrammatic view of a complete embodiment of the present invention with certain elements shown in block, and others in longitudinal section,

FIGURE 2 is a cross-sectional fragmentary view of the aerosol forming and charging section of the present invention.

FIGURE 3 is a cross-sectional view taken on line 3-3, looking in the direction of the arrows.

FIGURE 4 is a fragmentary view greatly enlarged taken on line 44 in FIGURE 1, looking in the direction of the arrows.

FIGURE 5 is a view in longitudinal section of a portion of a second embodiment of the present invention,

FIGURE 6 is a view in longitudinal section of a portion of a third embodiment of the present invention.

The invention broadly, according to one form of the invention, contemplates pumping the products of combustion through a conduit containing a charged aerosol of some suitable liquid such as water. The charged aerosol is preferably simultaneously formed and charged by a charging electrode, whereupon the fume particles are entrained by the charged aerosol droplets. The charged aerosol particles and droplets are then neutralized and coalesce to form larger droplets by the normal process of coagulation within uncharged aerosols. The large droplets and their entrained pollutants can then be collected or washed away.

Referring to the drawings, 10 indicates a conduit such as an automobile exhaust pipe, smoke stack, incinerator chimney or the like. The conduit 10 has an inlet end 11 and an outlet end 12, for the passage of the products of combustion in a carrier gas such as air. A suitable liquid such as water is led into the conduit 10 by means of a pipe 13 under pressure provided by a pump 14 The pipe 13 is connected to a reservoir 15 which contains the liquid and which, in the case of an automobile, may be the radiator of the vehicle. An array of capillary tubes 16 is disposed within the conduit 10, and is in communication with the liquid within the pipe 13. The capillary tubes 16 are similar in size to a small hypodermic needle and preferably have an internal diameter of 0.2 mm. or less. The discharged end 17 of the capillary tubes is supported by a thin block 30 held by the walls of the conduit 10.

A charging electrode 18 is disposed downstream of the ends of the capillary tubes 16, and spaced therefrom as shown in FIGURES 1 and 2. The electrode 18 which is in the form of a plurality of spaced vanes 19, is supported by an insulating plug 20 in the conduit 10. A DC. voltage source 21 is connected to the charging electrode 18 by means of the lead 22. A DC. voltage source of approximately 2,500 volts is suitable for the present invention. All of the elements in the system other than the charging electrode 18 are grounded.

in FIGURE 1, is disposed in one branch of the conduit By reason of thecharged electrode-18 an electricfield is established between the electrode 1 8 and the ends 17 of the capillary tubes 16. The liquid coming from the ends of the capillary tubes 16 is thus discharged into the conduit 10 in the form of a charged aerosol of minute liquid droplets 23, The droplets 23 have been marked with a plus sign to indicate a positive charge impressed thereon; but may be charged either positively or negatively.

The droplets 23 are combined with the products of combustion 24, moving through the conduit 10. As a result, fume particles carried by the exhaust gas 24 are entrained by the charged aerosol droplets in the charging region between the capillary array 16 and the electrode 18. The liquid droplets consisting of the charged aerosol and the fume particles traverse the electrode 18 as indicated at 23', in FIGURE 1.

A collector screen 25 in the form of a lattice is disposed acrossthe conduit 10 downstream of the electrode 18 aS shown in FIGURE 1. The collector screen is made of electrically conductive material and provided with a plurality of needle-like points 26 which extend in the direction of the electrode 18 and serve to discharge the droplets 23. The droplets 23, which are now neutral pass through the screen 25 and coalesce to form larger droplets 27 by the normal processes of coagulation within an uncharged aerosol. The larger droplets containing the fume particles therein emerge from the exit end 12 of the conduit 10 and may be collected or allowed to fall harmlessly to the ground as though they were rain drops.

If the fume suppressor is used in conjunction with the exhaust of an internal combustion engine it may be desirable to inject a small amount of a peroxide from a reservoir 28 into the pipe 13 so that it is mixed with the liquid therein. The peroxide will react with the carbon monoxide in the exhaust gases to form carbon dioxide and thereby eliminate the harmful fumes.

In order to compensate for variations in the amount of gases passing through the conduit 10 due to increases or decreases in the engine speed, the pump 14 should be connected directly to the engine in any suitable manner whereby increase in engine speed will increase the speed of the pump to force an increased amount of liquid into the conduit 10 so that a sufficient amount of charged aerosol is present within the conduit to entrain substantially all of the combustion products passing therethrough.

It has been found that only a small amount of liquid is necessary to produce a sufiicient amount of charged aerosol within the conduit 10 to entrain and carry off the products of combusition. In addition, the small DC. voltage and power requirements, and the nature of the charging and discharging elements within the conduit 10 make for a very compact and inexpensive fume suppressing device. Approximately .0l% to of the total gas by mass passing through conduit comprises the aerosol liquid droplets.

Referring to FIGURE 5, there is shown another form of fume suppressor made in accordance with the present invention in which the charged aerosol droplets 24, formed inthe manner set forth in connection with FIG- .URES 1-4, and with the particles of combustion entrained therein are picked up by a collector electrode 32 in the form of a metal sleeve carried within the conduit 10 and separated therefrom by a dielectric layer 31. The collector electrode is maintained at a negative voltage if the droplets are positively charged and at a positive voltage if the droplets are negatively charged. As a result, the droplets are attracted to the collector electrode 32 and coalesce thereon to form a liquid film 27 which will flow out or be blown out of the exit end 12 of the conduit 10,

Referring to FIGURE 6 there is shown still another embodiment of the present invention in which the conduit 10 is forked as indicated at 28 to provide two passageways for the products ofcombustion. A plurality of capillary tubes 16 connected to a pipe 13, similar to that shown 10. A second plurality of capillary tubes 16*, connected to a second pipe 13*, is disposed in the second branch of the conduit 10. A charging electrode 18 is held in the first branch spaced from the capillary tubes 16 and a second charging electrode 18 is similarly located in the second branch. A positive D.C. voltage is applied to the charging electrode 18 and a negative DC. voltage applied to the electrode 18*. As a result, the charged aerosol droplets 23 and 23 that emerge from the electrodes 18, 18 respectively, are oppositely charged. When the droplets 23, 23 meet where the forked portion 28 of the conduit 10 ends, as indicated at 29, theycoalesce and discharge each other, following which the neutralized dropmight appear in an automobile exhaust, it is to be understood that the conduit might constitute a vertical chimney or vent without departing from the spirit 'of the invention. In the case of a vertical vent some suitable means (not shown) for leading the large droplets 27 out of the chimney may be supplied, such means being well known within the art and forming no part of the present invention.

The present invention may also be used to detoxify or neutralize chemical wastes by'mixing well known reactants with the liquid of the aerosol. Thus, for example, fumes containing sulphuric acid or sulphurus acid can be reacted with sodium hydroxide dissolved in the charged droplets to render such fumes harmless. Alkaline type fumes can be treated with hydrochloric acid dissolved in the charged droplets, Nitric oxide (NO) can be absorbed with a solution of alkaline sulfite or dithionate.

Having thus fully described the invention, What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A charged aerosol fume suppressor comprising a conduit for the fumes, a source of fumes with a carrier gas connected to the conduit, a plurality of capillary tubes within the conduit, a source of liquid connected to the capillary tubes, a liquid dispensing end on the capillary tubes, a charging electrode spaced from the dispensing end of the capillary tubes, a source of potential connected to the charging electrode for applying an electric field between the charging electrode and the dispensing ends of the capillary tubes inthe presence of the fumes and liquid to simultaneously form and charge an aerosol, and means 'downstream of the charging electrode to receive and discharge the charged aerosol whereby the aerosol and the fumeds entrained therein coagulate to form a disposable iqui ' 2. A fume suppressor according to claim 1 in which the source of liquid includes an oxidant whereby harmful oxidizable gases in the fumes may be dctoxified.

3. A fume suppressor according to claim 1 in which all of the components except the charging electrode are maintained at ground potential. I

4. A fume suppressor according to claim 2 in which the oxidant is a'peroxide. v a

5. The method of suppressing fumes comprising passing said fumes through a conduit simultaneously forming and charging an aerosol by passing a liquid through a plurality of liquid containing and dispensing tubes in said,

conduit in the presence of an electric field, passing the charged aerosol and fumes through the conduit to combine them, neutralizing the charged aerosol by discharge means and allowing the neutralized aerosol droplets to coagulate into a disposableliquid- 6. The method of detoxifying fumes according to claim 5 in which an oxidant is added to the liquid of the aerosol.

7. A fume suppressor according to claim 1 in which the source of liquid contains a reactant, for acomponent of the carrier gas.

8. A fume suppressor according to claim 1 in which FOREIGN PATENTS the source of liquid contains an acid reactant.

9. A fume suppressor according to claim 1 in which 1436597 4/1966 France the source of liquid contains an alkali reactant. OTHER REFERENCES 5 Karmilova et a1.: Chem. Abstracts, vol. 56, p. 8050d References Cited (April 1962)- UNITED STATES PATENTS 2 753 195 Pmntiss 55 1 )7 OSCAR VERTIZ: Pnmary Exammer 2,841,242 7/1958 Hall 55-5 10 E. C. THOMAS, Assistant Examiner 2,983,332 5/1961 Vicard 55-5 3,091,069 5/1963 Braseficld ss s 3,257,779 6/1966 Strubler 55-123 23 4; 55 5, 3, 107, 122 

